Oocyte-secreted factors strongly stimulate sFRP4 expression in human cumulus cells.

Secreted frizzled-related protein-4 (SFRP4) belongs to a family of soluble ovarian-expressed proteins that participate in female reproduction, particularly in rodents. In humans, SFRP4 is highly expressed in cumulus cells (CCs). However, the mechanisms that stimulate SFRP4 in CCs have not been examined. We hypothesise that oocyte-secreted factors such as growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are involved in the regulation of SFRP4. Human CCs were collected from patients undergoing fertility treatments and treated with GDF9 or BMP15 or their combination in the presence of FSH or vehicle. FSH treatment significantly decreased SFRP4 mRNA levels when compared with nontreated cells. However, SFRP4 mRNA levels were increased significantly by GDF9 plus BMP15 in a concentration-dependent manner in the presence or absence of FSH. The combination of GDF9 plus BMP15 also increased SFRP4 protein levels and decreased the activity of the ß-catenin/T cell factor-responsive promoter significantly. GDF9 plus BMP15 inhibited steroidogenic acute regulatory protein and LH/hCG receptor stimulation by FSH, while treatment with SFRP4 blocked the stimulatory effect of FSH on these genes. The evidence demonstrates that GDF9 and BMP15 act in coordination to stimulate SFRP4 expression and suggests that SFRP4 mediates the anti-luteinising effects of the oocyte in human CCs.

Expression of the luteinizing hormone receptor (LHR) in ovarian cancer.

We investigated the association of LHR expression in epithelial ovarian cancer (OC) with clinical and pathologic characteristics of patients. LHR expression was examined immunohistochemically using tissue microarrays (TMAs) of specimens from 232 OC patients. Each sample was scored quantitatively evaluating LHR staining intensity (LHR-I) and percentage of LHR (LHR-P) staining cells in tumor cells examined. LHR-I was assessed as no staining (negative), weak (+ 1), moderate (+ 2), and strong positive (+ 3). LHR-P was measured as 1 to 5, 6 to 50% and >  50% of the tumor cells examined. Positive LHR staining was found in 202 (87%) patients' tumor specimens and 66% patients had strong intensity LHR expression. In 197 (85%) of patients, LHR-P was measured in > 50% of tumor cells. LHR-I was significantly associated with pathologic stage (p = 0.007). We found that 72% of stage III or IV patients expressed strong LHR-I in tumor cells. There were 87% of Silberberg's grade 2 or 3 patients compared to 70% of grade 1 patients with LHR expression observed in > 50% of tumor cells, p = 0.037. Tumor stage was significantly associated with overall survival and recurrence free survival, p < 0.001 for both analyses, even after adjustment for age, tumor grade and whether patient had persistent disease after therapy or not. Our study demonstrates that LHR is highly expressed in the majority of OC patients. Both LHR-I and LHR-P are significantly associated with either the pathologic stage or tumor grade.

Transition to the ovulatory season in mares: An investigation of antral follicle receptor gene expression in vivo.

The inability to obtain in vivo samples of antral follicle wall layers without removing the ovaries or sacrificing the animals has limited more in-depth studies on folliculogenesis. In this study, a novel ultrasound-guided follicle wall biopsy (FWB) technique was used to obtain in vivo follicle wall layers and follicular fluid samples of growing antral follicles. The expression of proliferative, hormonal, angiogenic, and pro-/antiapoptotic receptors and proteins in the follicular wall among three follicle classes were compared during the spring transitional anovulatory (SAN) and spring ovulatory (SOV) seasons in mares. The main findings observed in the granulosa, theca interna, and/or all follicle layers during the SOV season compared with the SAN season were (a) small-sized follicles (10-14 mm) had greater epidermal growth factor receptor (EGFR) and Bcl-2 expression; (b) medium-sized follicles during the expected deviation/selection diameter (20-24 mm) had greater expression of EGFR, Ki-67, luteinizing hormone receptor (LHR), and Bcl-2; and (c) dominant follicles (30-34 mm) had greater EGFR, Ki-67, vascular endothelial growth factor, LHR, and Bcl-2 expression. Estradiol related receptor alpha expression and intrafollicular estradiol concentration increased, along with an increase in follicle diameter in both seasons. In this study, the application of the FWB technique allowed a direct comparison of different receptors' expression among follicles in different stages of development and between two seasons using the same individuals, without jeopardizing their ovarian function. The successful utilization of the FWB technique and the mare as an experimental animal offer a great combination for future folliculogenesis studies on mechanisms of follicle selection, development, and ovulation in different species, including women.

Luteinizing hormone receptor expression by nonneoplastic and neoplastic canine lymphocytes.

OBJECTIVE: To investigate luteinizing hormone (LH) receptor expression in canine nonneoplastic and neoplastic lymph nodes, circulating nonneoplastic lymphocytes, and T-cell lymphoma (TCL) cell lines. SAMPLE: Formalin-fixed, paraffin-embedded lymph nodes (5 neoplastic and 3 nonneoplastic) from 6 dogs, circulating lymphocytes from venous blood specimens obtained from 12 healthy dogs, and 3 TCL cell lines derived from 3 dogs with primary lymphoma. PROCEDURES: Lymph node specimens were immunohistochemically stained for determination of LH receptor expression. Circulating nonneoplastic lymphocytes and TCL cell lines were evaluated for LH receptor expression by use of flow cytometry; circulating lymphocytes were also immunophenotyped. The mean percentage of cells positive for LH receptors was determined for each type of specimen. For the healthy dogs, percentages of circulating B and T lymphocytes that expressed LH receptors were assessed on the basis of sex and reproductive status. RESULTS: The mean percentage of LH receptor-positive cells in canine neoplastic and nonneoplastic lymph nodes was 12.4% and 4.1%, respectively. For the healthy dogs, the mean percentage of circulating LH receptor-positive T lymphocytes was significantly higher in gonadectomized dogs (16.6%) than in sexually intact dogs (10.5%); the percentages of circulating LH receptor-positive B lymphocytes did not significantly differ by reproductive status. Among the 3 canine TCL cell lines, LH receptor expression ranged from 10% to 45%. CONCLUSIONS AND CLINICAL RELEVANCE: In this study, LH receptor expression by canine neoplastic and nonneoplastic lymphocytes was detected. Research into the effects of downregulation of LH receptor activation in dogs with lymphoma is warranted.

The effect of clomiphene citrate and human chorionic gonadotropin on the expression of CatSper1, CatSper2, LHCGR, and SF1 genes, as well as the structural changes in testicular tissue of adult rats.

The purpose of this study was to investigate the effect of clomiphene citrate and human chorionic gonadotropin (HCG) on the structural changes, as well as the evaluation of the expression of cation channel sperm-associated protein 1 (CatSper1), cation channel sperm-associated protein 2 (CatSper2), luteinizing hormone/choriogonadotropin receptor (LHCGR), and steroidogenic factor 1 (SF1) genes in testicular tissue of rats. All rats divided into five groups as follows; G1 as the control group that received normal saline, G2 received olive oil, G3 received 100 IU/kg HCG, G4 received 5 mg/kg clomiphene citrate, and G5 received 5 mg/kg clomiphene citrate and 100 IU/kg HCG. At the end of the experiment period, Day 56, blood samples were taken and the serum was isolated. Then, histomorphometric analysis, hormonal assess, and real-time polymerase chain reaction to measure the expression of CatSper1, CatSper2, LHCGR, and SF1 genes were performed. The results showed that the concentrations of testosterone, follicle-stimulating hormone, and luteinizing hormone were decreased in the G4 group, whereas these parameters were increased in the G3 group. A comparison of the sperm quality indicated a significant reduction in the quality of sperm cells in the G4 group compared with other groups. The quality of sperm was significantly enhanced in the G3 and G5 groups in comparison with the G1 group. Also, our findings demonstrated that the expression of CatSper1, CatSper2, LHCGR, and SF1 genes were significantly elevated in the G3 group when compared with other experimental groups. According to the obtained results, it seems that clomiphene citrate reduces the process of spermatogenesis and the detrimental impacts of this compound would be neutralized by the administration of HCG.

Effects of hCG on reduced numbers of hCG receptors in the prefrontal cortex and cerebellum of rat models of Alzheimer's disease.

Age-associated changes in the levels of luteinizing hormone and human chorionic gonadotropin (hCG) are potential risk factors for Alzheimer's disease (AD); hCG concentration is related to the incidence of AD. The highest density of hCG receptors is in zones of the brain that are vulnerable to AD and streptozotocin (STZ) can decrease the density of this receptor. We investigated the effects of different doses of hCG on hCG receptor density in the prefrontal cortex and cerebellum in a rat model of STZ-induced AD. AD was induced by intracerebroventricular injection of 3 mg/kg STZ. The resulting AD rats were treated for 3 days with 50, 100 or 200 IU/200 µl hCG, or with saline as a control. Sections of prefrontal cortex and cerebellum were stained immunohistochemically and hCG receptor-immunoreactive (ir) neurons were counted. STZ injected into the lateral ventricles of rat brains reduced the density of hCG receptor-ir neurons in the prefrontal cortex and cerebellum. hCG administration resulted in a significant dose-dependent increase in the number of hCG receptor-ir neurons in the prefrontal cortex and cerebellum. The maximum increase in the number of receptors occurred following the 200 IU dose of hCG. Administration of hCG ameliorated the lowered density of hCG receptor-ir neurons in the cerebellum and prefrontal cortex in STZ-induced AD rats.

Expression and localisation of FSHR, GHR and LHR in different tissues and reproductive organs of female yaks.

BACKGROUND: This study aimed to investigate the expression and localisation of fol-licle stimulating hormone receptor/growth hormone receptor/luteinising hormone receptor (FSHR/GHR/LHR) in different tissues and examine the regulatory effects of FSHR/GHR/LHR in the reproductive organs of female yaks during luteal phase. MATERIALS AND METHODS: The quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry assays were utilised to analyse the expression and localisation of FSHR/GHR/LHR in different tissues on female yaks. RESULTS: The qRT-PCR results showed that the mRNA expressions of FSHR/GHR/ /LHR were significantly different in the non-reproductive organs (p < 0.01); the highest expression level was observed in the kidney, cerebellum and lung, whereas the lower expression level was observed in the liver and spleen. Im-munohistochemistry assay results showed that FSHR/GHR/LHR were located in kidney tubules, Purkinje cells, cerebellar medulla, alveolar cells and hepato-cytes. In addition, the expression levels of FSHR and GHR were considerably higher than LHR in the reproductive organs of female yaks during luteal phase (p < 0.01). FSHR/GHR/LHR were located in cardiac muscle cells, cerebellar medulla, and theca cell lining of reproductive organs. Furthermore, the expression level of FSHR was higher than those of GHR and LHR in all examined tissues. CONCLUSIONS: Therefore, the expression and localisation of FSHR/GHR/LHR possibly helped to evaluate the effects of them in tissue specific expression on female yaks, investigate the function and mechanism of FSHR/GHR/LHR in the reproductive organs of female yaks during luteal phase. (Folia Morphol 2018; 77, 2: 301-309).

The role of Melatonin receptor MTNR1A in the action of Melatonin on bovine granulosa cells.

Granulosa cells (GCs) play an important role in ovarian follicle growth, development, and follicular atresia. In the present study, we investigated the effects of Melatonin on bovine GCs, and asked if MTNR1A was involved in their response to this indole hormone. Our results indicated that Melatonin inhibited GC apoptosis by up-regulating the expression of BCL2, BCL-XL, GPX4, and SOD1, and down-regulating the expression of BAX, CASP3, and TP53. Moreover, Melatonin modulated bovine GC function by decreasing the expression of INHA, INHBB, FSHR, and TGFBR3, and the abundance of Inhibin ß and Activin B, while increasing the expression of LHR, INHBA, and secretion of progesterone by GCs. In contrast, knockdown of MTNR1A significantly increased the expression of BAX, CASP3, TP53, INHA, FSHR, and TGFBR3, as well as Inhibin ß abundance, while decreasing the expression of BCL2, GPX4, SOD1, and LHR, and production of progesterone and estradiol; no effect was observed on the expression of BCL-XL, INHBA, or INHBB. These results suggest that Melatonin and MTNR1A play an important role in modulating bovine GC function by regulating cellular progression, apoptosis, hormones secretion, and reproduction-related genes. Furthermore, altered expression of MTNR1A could affect how bovine GCs respond to Melatonin.

Prohibitin: targeting peptide coupled to ovarian cancer, luteinization and TGF-ß pathways.

BACKGROUND: Ovarian epithelial tumor (OET) is a silent disease of late diagnosis and poor prognosis. Currently treatment options are limited and patient response to treatment is difficult to predict so there is a serious need to delineate the real pathogenesis to predict tumour prognosis. Prohibitin (PHB) is an evolutionarily protein that regulates the cell cycle. TGF-ß has been shown to be a positive and negative regulator of cellular proliferation and differentiation. The present study provides an overview on the role played by PHB1, TGF-ß and LH in ovarian cancer. METHODS: The study was conducted on 60 patients with ovarian tumors (benign, borderline and malignant) and 20 healthy volunteers. LH and TGF-ß serum levels were measured by ELISA. Expression of prohibitin and LHR-mRNA were assessed by IHC and TaqMan® real time gene expression assay, respectively. RESULTS: Serum levels of LH and TGF-ß were significantly decreased among borderline and malignant groups. There was significant over-expression of LHRmRNA in malignant group. Prohibitin expression was significantly increased in malignant ovarian tissue. Strong negative correlations were found between LHR mRNA expression and serum LH levels, and between IHC score of prohibitin and serum levels of LH among patients with borderline ovarian tumors. CONCLUSION: Steady decline of LH and TGF-B serum levels, from benign cystadenoma to borderline tumor to carcinoma, suggests their inhibitory role against OET cell growth. Increased PHB1 expression in OET suggests its proliferative activity that can be regulated by luteinisation and/or TGF-ß. Furthermore increased LHR mRNA tissue expression can provide hope for using LH in treatment of some types of ovarian cancers.

Time- and Dose-Dependent Effects of 17 Beta-Estradiol on Short-Term, Real-Time Proliferation and Gene Expression in Porcine Granulosa Cells.

The key mechanisms responsible for achievement of full reproductive and developmental capability in mammals are the differentiation and transformation of granulosa cells (GCs) during folliculogenesis, oogenesis, and oocyte maturation. Although the role of 17 beta-estradiol (E2) in ovarian activity is widely known, its effect on proliferative capacity, gap junction connection (GJC) formation, and GCs-luteal cells transformation requires further research. Therefore, the goal of this study was to assess the real-time proliferative activity of porcine GCs in vitro in relation to connexin (Cx), luteinizing hormone receptor (LHR), follicle stimulating hormone receptor (FSHR), and aromatase (CYP19A1) expression during short-term (168 h) primary culture. The cultured GCs were exposed to acute (at 96 h of culture) and/or prolonged (between 0 and 168 h of culture) administration of 1.8 and 3.6 µM E2. The relative abundance of Cx36, Cx37, Cx40, Cx43, LHR, FSHR, and CYP19A1 mRNA was measured. We conclude that the proliferation capability of GCs in vitro is substantially associated with expression of Cxs, LHR, FSHR, and CYP19A1. Furthermore, the GC-luteal cell transformation in vitro may be significantly accompanied by the proliferative activity of GCs in pigs.

Triptorelin and cetrorelix induce immune responses and affect uterine development and expressions of genes and proteins of ESR1, LHR, and FSHR of mice.

CONTEXT: GnRH immunity can reduce the expression of pituitary GnRH levels, and cause the changes in reproductive behaviors. It is unclear whether triptorelin (TRI) and cetrorelix (CET) immunity influences uterine development and expression of follicle-stimulating hormone receptor (FSHR), luteinizing hormone receptor (LHR), and estradiol receptor 1 (ERS1) in the uterus. OBJECTIVE: The study investigated the effects of active immunity of GnRH agonist and antagonist on uterine development, microstructures, expression of hormone receptors mRNAs, and proteins in uteri. MATERIALS AND METHODS: One hundred and five mice were assigned into CET, TRI, and control groups (CG). Mice in CET-1, CET-2, and CET-3 (n = 15) were subcutaneously injected with 10, 20, and 40 µg CET antigens for seven days, respectively. Mice in TRI-1, TRI-2, and TRI-3 were injected with 10, 20, and 40 µg TRI antigens for seven days, respectively. The qPCR and Western blot were implemented to determine expressions of ESR1, LHR and FSHR mRNAs, and proteins. RESULTS: Compared with CG, the uterine weights of CET-1, CET-2, and CET-3 increased by 42.86, 62.86, and 10.00% on day 35 (p < 0.05), respectively. Uterine weights of TRI-2, TRI-3 reduced by 28.57% and 11.43% (p < 0.05), respectively. The uterine cavity in CET-1, CET-2, and CET-3 increased; the uterine wall became thick. The cytoplasm of endometrial epithelial cells (EEC) increased slightly. In TRI group, the uterine wall thinned. Uterine cavity became narrow slightly in TRI-1. Numbers of uterine glands reduced. The endometrium epithelial thickness (EET) in CET-1 and CET-2 increased by 68.21% and 79.46% (p < 0.05), respectively. EET in TRI-1 was decreased by 13.69%. Uterine wall thicknesses (UWT) in CET-1 and CET-2 were higher than CG, with the increment of 28.59% and 30.72%. UWT of TRI-1, TRI-2, and TRI-3 reduced by 29.35, 15.36, and 14.41%, respectively. Expressions of ESR1, FSHR, and LHR mRNAs in CET and TRI mice increased. ESR1 and FSHR protein levels increased in all experimental mice (p < 0.05), with a maximum of TRI-3. LHR protein levels of the CET decreased. LHR protein levels of TRI group increased, with a maximum of TRI-3 (p < 0.05). ESR1 protein level had significant negative correlations to mRNA expressions of ESR1, LHR, and FSHR. CONCLUSIONS: CET immunity promoted the uterine development, improved EET and UWT, and also promoted the expressions of ESR1 and FSHR protein levels. It lessened the LHR protein levels. TRI immunity blocked EET and UWT, inhibited uterine growth and development. The efficacy of CET immunity was more obvious than TRI.

Effects of Dietary Selenium Supplementation on Seminiferous Tubules and SelW, GPx4, LHCGR, and ACE Expression in Chicken Testis.

We investigated the effects of dietary selenium (Se) supplementation on the development of chicken testis and the expression of selenoprotein W (SelW), glutathione peroxidase4 (GPx4), luteinizing hormone/choriogonadotropin receptor (LHCGR), and angiotensin converting enzyme (ACE). Sixty roosters were assigned randomly into the control group fed with a basic diet (containing 0.3 mg Se/kg) and the experimental group fed with a diet (containing 0.6 mg Se/kg). The testes were collected individually at age of 6, 9, and 12 weeks. Se was supplemented in chicken feed for 15 days before sampling. The results indicated that dietary Se affected the number of cells in the seminiferous tubules and viability of Sertoli cells in vitro culture. SelW and GPx4 expression in the testes increased significantly in the experimental group compared to that in the control group. LHCGR expression in the testes increased significantly in the experimental group after 12 weeks compared to that in the control group. In contrast, ACE expression was inhibited in the experimental group compared to that in the control group. These results suggest that dietary supplementation with Se improved development of the seminiferous tubules at the cellular level and that SelW, GPx4, LHCGR, and ACE are involved.

Cisplatin Induces Overactivation of the Dormant Primordial Follicle through PTEN/AKT/FOXO3a Pathway which Leads to Loss of Ovarian Reserve in Mice.

Cisplatin is a first-line chemotherapeutic agent for ovarian cancer that acts by promoting DNA cross links and adduct. However drug resistance and considerable side effects including reproductive toxicity remain a significant challenge. PTEN is well known as a tumor suppressor function which plays a fundamental role in the regulation of the cell cycle, apoptosis and development of cancer. At the same time PTEN has been revealed to be critically important for the maintenance of the primordial follicle pool. In this study, we investigated the role of PTEN/Akt/FOXO3 pathway in cisplatin-induced primordial follicle depletion. Cisplatin induced ovarian failure mouse model was used to evaluate how this pathway involves. In vitro maturation was used for oocyte rescue after cisplatin damage. We found that cisplatin treatment decreased PTEN levels, leading to a subsequent increase in the phosphorylation of key molecules in the pathway. The activation of the PTEN/Akt/FOXO3 pathway cascade increased cytoplasmic translocation of FOXO3a in cisplatin-treated follicles, which in turn increased the pool size of growing follicles, and rapidly depleted the number of dormant follicles. Once activated, the follicles were more prone to apoptosis, and their cumulus cells showed a loss of luteinizing hormone (LH) receptor expression, which leads to failure during final maturation and ovulation. In vitro maturation to rescue oocytes in a cisplatin-treated mouse model resulted in successful maturation and fertilization. This study is the first to show the involvement of the PTEN/Akt/FOXO3 pathway in premature ovarian failure after cisplatin treatment and the possibility of rescue through in vitro maturation.

Fetal Leydig Cells Persist as an Androgen-Independent Subpopulation in the Postnatal Testis.

Two distinct types of Leydig cells emerge during the development of eutherian mammals. Fetal Leydig cells (FLCs) appear shortly after gonadal sex differentiation, and play a crucial role in masculinization of male fetuses. Meanwhile, adult Leydig cells (ALCs) emerge after birth and induce the secondary male-specific sexual maturation by producing testosterone. Previous histological studies suggested that FLCs regress completely soon after birth. Furthermore, gene disruption studies indicated that androgen signaling is dispensable for FLC differentiation but indispensable for postnatal ALC differentiation. Here, we performed lineage tracing of FLCs using a FLC enhancer of the Ad4BP/SF-1 (Nr5a1) gene and found that FLCs persist in the adult testis. Given that postnatal FLCs expressed androgen receptor (AR) as well as LH receptor (LuR), the effects of AR disruption on FLCs and ALCs were analyzed by crossing AR knockout (KO) mice with FLC-specific enhanced green fluorescent protein (EGFP) mice. Moreover, to eliminate the influence of elevated LH levels in ARKO mice, LuRKO mice and AR/LuR double-KO mice were analyzed. The proportion of ALCs to postnatal FLCs was decreased in ARKO mice, and the effect was augmented in the double-KO mice, suggesting that androgen signaling plays important roles in ALCs, but not in FLCs. Finally, ARKO was achieved in an FLC-specific manner (FLCARKO mice), but the FLC number and gene expression pattern appeared unaffected. These findings support the conclusion that FLCs persist as an androgen-independent Leydig subpopulation in the postnatal testis.

A new variant in signal peptide of the human luteinizing hormone receptor (LHCGR) affects receptor biogenesis causing leydig cell hypoplasia.

The human luteinizing hormone/chorionic gonadotropin receptor (LHCGR) plays a fundamental role in male and female reproduction. In males, loss-of-function mutations in LHCGR have been associated with distinct degrees of impairment in pre- and postnatal testosterone secretion resulting in a variable phenotypic spectrum, classified as Leydig cell hypoplasia (LCH) type 1 (complete LH resistance and disorder of sex differentiation) and type 2 (partial LH resistance with impaired masculinization and fertility). Here, we report the case of an adolescent who came to the pediatric endocrinologist at the age of 12 years old for micropenis and cryptorchidism. Testis biopsy showed profound LCH and absent germinal line elements (Sertoli-only syndrome). The sequence analysis of the LHCGR gene showed the presence of a compound heterozygosity, being one variation, c.1847C>A p.S616Y, already described in association to Hypergonadotropic Hypogonadism, and the other, c.29 C>T p.L10P, a new identified variant in the putative signal peptide (SP) of LHCGR. Functional and structural studies provide first evidence that LHCGR have a functional and cleavable SP required for receptor biogenesis. Moreover, we demonstrate the pathogenic role of the novel p.L10P allelic variant, which has to be considered a loss-of-function mutation significantly contributing, in compound heterozygosity with p.S616Y, to the LCH type 2 observed in our patient.

Hypusination of eukaryotic initiation factor 5A via cAMP-PKA-ERK1/2 pathway is required for ligand-induced downregulation of LH receptor mRNA expression in the ovary.

Luteinizing hormone receptor (LHR) mRNA expression in the ovary is regulated post-transcriptionally by an LH receptor mRNA binding protein (LRBP). Eukaryotic initiation factor 5A (EIF5A), identified as an LRBP-interacting protein plays a crucial role in LHR mRNA expression. In this study, we have demonstrated that during hCG-induced LHR downregulation, a significant upregulation of eIF5A mRNA expression and hypusination of eIF5A protein occurs in a time dependent manner. Pretreatment with H89, a specific inhibitor of PKA, and U0126, a specific inhibitor of ERK1/2 significantly inhibited both hCG-induced eIF5A mRNA expression and hypusination of eIF5A protein. Pretreatment with GC7, a specific inhibitor of eIF5A hypusination significantly abolished hCG-induced LRBP mRNA and protein expression. Furthermore, GC7 pretreatment significantly inhibited hCG-induced interaction of LRBP with LHR mRNA as assessed by RNA electrophoretic mobility gel shift assay (REMSA). GC7 treatment also reversed LHR mRNA downregulation. Taken together, these results suggest that hCG-induced LHR mRNA downregulation is mediated by cAMP-PKA-ERK1/2 signaling leading to activation of eIF5A hypusination.

Effects of luteinizing hormone receptor signaling in prostate cancer cells.

BACKGROUND: The importance of androgen signaling in prostate cancer (PC) is well described and prostate cancer cells retain the ability to directly synthesize androgens. Luteinizing hormone (LH) can induce expression of steroidogenic enzymes and trigger androgen production, but the regulation of this process is not well-described. Here, we explored the impact of silencing LH receptor (LHR) silencing on androgen synthesis and on several relevant signaling pathways in PC. METHODS: LHR mRNA and protein expression was evaluated in LNCaP PC cells treated with LHR-siRNA. MTS assay was used to measure the effect of LHR-siRNA on proliferation in LNCaP and 22RV1 PC cells. Treated LNCaP and LAPC-3 cells were also assayed for differences in androgen synthesis and expression of steroidogenic enzymes, PSA, AR, and critical signaling molecules including PKA, ERK1/2, PI3K, AKT2, and HER2. RESULTS: We confirmed that functional LHR is expressed in both androgen-sensitive and castrate-resistant PC specimens. Treatment with LHR-siRNA effectively silenced LHR gene and protein expression and prevented LH-mediated proliferation and androgen synthesis in prostate cancer cells. LHR silencing also downregulated expression of AR, PSA, PKA, ERK1/2, PI3K, AKT2, and HER2. CONCLUSION: Collectively, these data demonstrate that silencing LHR expression suppresses androgen synthesis and signaling and the LH-LHR pathway may represent a viable therapeutic strategy in PC.

Association between the expression of LHR, FSHR and CYP19 genes, cellular distribution of encoded proteins and proliferation of porcine granulosa cells in real-time.

The process of granulosa cell luteinization is part of the main process determining growth, differentiation and proliferation of these cells. Although the mechanisms underlying the regulation of luteinizing hormone receptor (LHR), follicle stimulating hormone receptor (FSHR) and cytochrome P450 aromatase expression in mammalian granulosa cells is well understood, still little is known about the expression of mRNA and encoded proteins in relation to cell proliferation and luteinization in vitro. Porcine granulosa cells were observed in vitro at a168-h period while undergoing real-time proliferation using an RTCA system. Furthermore, LHR, FSHR and CYP19 mRNA expression were detected using RQ-PCR after 168 h of in vitro culture (IVC) at 24-h intervals, and LHR, FSHR and P450arom were examined by confocal microscopic observation at 0 h, 24 h, 48 h, 96 h, and 168 h of IVC. We found increased expression of LHR and CYP19 mRNA at 24 h and 48 h of IVC compared to the other stages (P less than 0.01, P less than 0.001), whereas FSHR mRNA was higher only at 0 h (P less than 0.001). In contrast, LHR, FSHR and P450arom protein expression was significantly higher at the end of the 168-h IVC period compared to 0 h, 24 h, 48 h and 96 h (P less than 0.001). LHR, FSHR and P450arom were distributed in the cytoplasm of porcine GCs at each time point of IVC. When analyzing cell proliferation, differences in cell index were observed (at least P less than 0.05) between the first (0-24 h) and the last period (144-168 h) of IVC; however, soon after 24 h of IVC a logarithmic increase in proliferation was also seen. We assume that the expression of LHR, FSHR and CYP19 mRNAs depends on the period of in vitro cultivation and may be linked with the luteinization process of porcine GCs. Furthermore, the patterns of mRNA and protein expression suggest a post-transcriptional regulation of LHR, FSHR and P450arom. In summary, it can be presumed that mRNA and protein expression and in vitro luteinization and proliferation of porcine GCs are regulated by different mechanisms, because not all of these processes are correlated.

Melatonin-mediated effects on killifish reproductive axis.

The aim of this study was to investigate the melatonin-mediated effects upon the neuroendocrine axis of the brackish killifish (Fundulus heteroclitus), a suitable experimental model to study reproductive events. The ability of melatonin to enhance reproductive capacity (fecundity, embryo survival and hatching rate) inducing the transcriptional activity of gonadotropin releasing hormone (gnrh), luteinizing hormone receptor (lhr) and melatonin receptor (mtnr) was investigated in adult females. Moreover, the melatonin-mediated enhancement of killifish sperm motility and velocity was found consistent with higher fecundity of melatonin-exposed fishes. As a further extent, Fourier Transform Infrared (FT-IR) microspectroscopy evidenced a reduction of lipid unsaturation level on isolated spermatozoa from treated males. Moreover, the reduction of mtnr gene expression during embryo development and lower biometric parameters documented in the larvae from melatonin-exposed parents suggest that melatonin acts as a hormonal mediator able to transfer the environmental signal to oocytes and then to embryos as inheritance of adaptive environmental changes. These results support the positive role of melatonin on killifish reproduction and its role as a maternal factor on embryo and larval development.